The prior art includes many patents showing rollers of the present general type which are useful particularly for rolling small patches in a roadway and for rolling shoulder areas. These rollers are generally towed behind a truck or a tractor and have some means for raising the drum off of the ground to permit high speed transport of the roller to a new location along the roadway without damaging the latter during such transport. U.S. Pat. No. 2,986,977 to Swenson; U.S. Pat. No. 2,962,950 to Martin; U.S. Pat. No. 3,665,823 to Chaney; and U.S. Pat. No. 3,895,880 to Fink are of this type, the latter three patents including hydraulic cylinder means for raising the drum clear of the ground using the vehicle's hydraulic system, but at the expense of transferring the weight of the roller to the suspension and wheels of the vehicle.
U.S. Pat. No. 2,830,511 to Wills and U.S. Pat. No. 3,477,535 to Wyatt show rollers attached to a vehicle and lowerable by hydraulic means to raise one end of the vehicle from the ground, these disclosures using a second hydraulic cylinder to steer the roller when the vehicle is raised thereby. U.S. Pat. No. 2,386,025 to Wills is also of this same general type, but it includes means whereby the roll can be both steered and off-set from the center line of the towing vehicle to positions which can then be maintained by dropping a pin into a locating hole. U.S. Pat. No. 2,986,977 to Swenson and U.S. Pat. No. 3,071,051 to Martin show drum wetting devices from which the flow of water is controlled, the latter patent showing automatic means for turning on the water supply when the drum is in rolling position.